Practice ionic compound formula determination by using ionic valences.
Discuss why ionic compounds are crystalline and not units.
View diagram of sodium chloride crystal.
Discuss lattice energy.
Determine why sodium fluoride has a greater lattice energy than the chl=oride or the iodide by determining the inter-ionic distances and graphing them vs. the lattice energies.
Elicit that the lattice energy is directly related to the size of the ions bonded, smaller ionic radii produce stronger inter-ionic forces and greater lattice energy.
Discuss physical properties as a function of inter-ionic forces, how strongly the particles are attracted to each other.